7.3 won't start

[poppy]

I have a 94 7.3 that sat for a time. Now it will not start, won't even attempt to fire even with a shot of starting fluid. Anyone have any ideas where to start looking. Thanks Poppy

[White95f250]

Need more info, how long did it sit? How many miles etc

[poppy]

White95, I bought another truck so this one would sit for a 4 to 6 weeks at a time then I would start it and take it for a 10 mile drive. After a few months I went to take it for drive and nothing. Changed cam sensor and still nothing. Want to sell it so the other day I decided to get it in barn and try to get it running. Noticed when I try to start there is no smell of fuel even at the exhaust. Tried small amount of starting fluid and still nothing. 160k miles and was running fine when I parked it. Poppy

[bondsman]

Check the hpop reservoir. Probably empty. Just fill it up and give it a go.

Are you getting the wait to start light? If not, check maxi fuse 22 under the hood. If it is popped, disconnect the fuel bowl heater, replace the fuse and it should be good.

[poppy]

Is it possible to unplug the wire to injectors on the valve covers and test with volt meter to see if they are getting fire. Poppy

[bondsman]

Start with the small stuff... Are you getting the wait to start light? If not, check maxi fuse #22 under the hood. If that fuse is blown, chances are the fuel bowl heater is shorted. The fuel bowl heater is on the driver's side of the fuel bowl, second connector up from the bottom. Just cut the wire, tape it up, replace the fuse and you should be in business.

If you are getting the wait to start light, check the hpop oil level. The "high Pressure Oil Pump reservoir is located in the middle, front of the engine. Looking down on it, you will see the oil pressure sensor on the passenger side of it with one connector going to it. On the driver's side of the reservoir, you will see a plug that either an allen socket or a 1/4" drive extension will fit it. Remove that plug and see if there is oil in there. If not, fill it up and give it a shot.

If the hpop is full, try uplugging the icp sensor to see if it will start. The Injector Control Pressure sensor is located in the drivers side oil rail on top of the head with a three wire connector going to it. By unplugging it, a default command is sent to the ipr and allows pressure to build. This procedure will tell you if the icp is bad.

Try those and post back any results.

[poppy]

HPOP was very low, almost 1/2 inch of oil. Filled it and still no go. Fuse and fuel bowl seem OK. will try the icp sensor tomorrow. Thanks POPPY

[bondsman]

Does the hpop stay full after cranking it over? If not, it could be that it is leaking down, the oil rails are empty, or the low pressure oil pump has failed.

The low pressure oil pump (easy to change, external on the crank, behind the dampner) feeds oil to the hpop reservoir. The hpop sends the oil from the reservoir to the oil rails and build pressure (2000psi+). Maybe the oil rails are just too empty and you need to fill the hpop reservoir a few times. Try filling it up, crank a few times, check and refill hpop reservoir, crank and check. The lpop is working if it keeps the reservoir full (once the oil rails are full).

There is a fuse you can pull for the idm (I don't remember which one it is) or you could unplug the IDM (computer on the drivers fender well towards the fire wall), then crank it over a few times to prime the system. This keeps the injectors from firing and dumping the oil from the rails. Just check the hpop reservoir between cranks and top it off.

[poppy]

Got it going today, this has been going on for about three years off and on. Was about to pull the IPR and rebuild it but could not find kit. Just sit down looking at it and thinking about all I have read the last few days about all the pressures that have to build up for this to start oil, fuel, etc. Figured the only way to create a lot of pressure was to really turn that engine over so called a buddy of mine. We put a tow rope on it and took off down the road about 100yards and 45 mph it fired up. HPOP was very low from sitting so long along with some other small things so your advice to start with the small things was right on. Thanks. Poppy

[sgg93]

I've rolled off lots of trucks...but i gotta say i've never done one with a tow rope at 45mph. Glad you got it running.